The present invention relates generally to a combustor dome for a gas turbine engine and, in particular, to a one-piece combustor dome which connects directly to the liner and cowl of the combustor.
It is well known within the combustor art of gas turbine engines that a dome portion, in conjunction with inner and outer liners, serves to form the boundary of a combustion chamber. A mixture of fuel and air is ignited and burned in such combustion chamber so that the products thereof are able to interface with the blades of turbines and produce work through one or more shafts. The annular combustor dome also serves to position a plurality of mixers in a circumferential manner so that the fuel/air mixture is provided in a desired manner. Because of its proximity to the combustion chamber hot gases and the extreme temperatures produced therein, the dome must be configured to withstand the harsh environment.
While previous designs have disclosed connecting the dome and liner portions downstream of the dome, this subjected the connection to the hot temperatures of the combustion chamber and interrupted the flow of cooling air along the liners. Accordingly, it became preferable to locate the connection of the dome and liners, as well as the respective cowls, upstream of the dome. In a current design, an intermediate member (such as a rivet band) has been utilized to indirectly connect the dome to an adjacent liner and cowl. Moreover, the intermediate member is typically brazed to the dome and requires additional time and effort in the manufacturing cycle.
Another combustor configuration is depicted in U.S. Pat. No. 3,990,232 to Campbell, where a dome having an integral V-shaped cross section has an apex portion from which first and second legs depend. As this design is currently employed, a pair of forgings requiring two weldings each is utilized. This further complicates the manufacturing cycle and extends the time required therefor.
Thus, in light of the foregoing, it would be desirable for a combustor dome configuration to be developed which simplifies its assembly and eliminates timely and costly operations from the manufacturing cycle. It is also desirable for weight in the dome and liner sections to be reduced where possible. At the same time, the functional characteristics of the combustor are preferably maintained with the previous design, including the amount and flow of cooling air supplied, so that recertification of the engine is avoided.
In a first exemplary embodiment of the invention, a combustor for a gas turbine engine having a longitudinal axis extending therethrough is disclosed as including an inner liner, an outer liner spaced radially from the inner liner, an annular dome connected to the inner and outer liners, a plurality of fuel/air mixers connected to the dome and circumferentially spaced within the dome, an outer cowl connected to the outer liner, and an inner cowl connected to the inner liner, wherein a combustion chamber is formed by the inner liner, the outer liner and the dome. The dome further includes a first end connected to the outer liner of the combustor, a second end spaced radially from the first dome end and connected to the inner liner of the combustor, a first portion extending rearwardly from the first end adjacent the outer liner, a second portion extending rearwardly from the second end adjacent the inner liner, a third portion extending from an inner diameter thereof and flaring radially outwardly with respect to the longitudinal axis, a fourth portion extending from an inner diameter thereof and flaring inwardly with respect to the longitudinal axis, an arcuate fifth portion connecting the first and third dome portions, and an arcuate sixth portion connecting the second and fourth dome portions.
In a second exemplary embodiment of the invention, an annular dome for a combustor of a gas turbine engine having a longitudinal axis extending therethrough is disclosed as including: a first end connected to a fuel/air mixer of the combustor; a second end connected to a liner of the combustor; a first portion extending rearwardly from the first end and flaring radially outward from the longitudinal axis; a second portion extending rearwardly from the second end adjacent the liner; and, an arcuate third portion connecting the first and second dome portions.